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Reliability DEM

Hi,

as a landscape planing office, the function of creating DEM`s with photogrammetry is a huge advantage. 
Unfortunately, I found out that the results of the DEM are very inaccurate compared to a laser scan. There were indifferences of up to one meter and sometimes the heights were displayed incorrectly. 

My hardware and settings were as follows:
- DJI Mavic Pro 2 (Hasselblad)
- Altitude 120 m
- Overlap 80/80
- Speed 8.2

The overlay report showed a result of 13+

Maybe you can share your experiences or describe how to proceed to generate a reliable DEM.

Thanks in advance,
Michel 

Michael Bolender

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Yeah, laser scans are cool but the gear to do it costs 50X... 

Cover an area that is larger than what you need. The edges get less overlap and thus have lower accuracy. 

User Terrain Awareness in your data collection. 

Relative measurements should be pretty solid but will certainly have a cumulative error as the distance of the measurement area increases.

Use GCPs to apply linear corrections to the elevation. 

120 meters is really high if you want to be getting good detail. 

80% overlap should be good but your most recent map is showing overlap of roughly 60% overlap. 

Zane 1 vote
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